1. Field of the Invention
This invention relates to a gate valve for controlling the flow of particulate material from a vessel or in a pipeline and more particularly to controlling the flow of plastic pellets with a valve that also seals an air line or a vacuum line.
2. Description of the Prior Art
Gate valves have been utilized to control the flow of particulate material by having a gate that opens and closes to permit material to flow through the valve when the valve gate is open. With particulate material, difficulties have been encountered in closing the gate securely since particulate material can jam between the end of the gate and the passage through which the material passes to keep the gate from completely closing. Under such conditions, the valve does not seal the air line or vacuum line in which it is utilized.
Some examples of earlier designs for valves that control particulate material may be found in the following patents: U.S. Pat. Nos. 1,295,540; 2,077,980; 2,207,120; 2,505,697; 2,852,167; 2,983,408; 3,581,954; 3,623,639; and 4,531,658.
The present invention is directed to a gate valve which effectively controls the flow of particulate material, particularly plastic pellets, through the gate valve. The present invention has a valve gate with an angled leading edge and a notch formed in it to permit the valve gate to push away particulate material that may prevent it from completely closing. The body of the valve of the present invention has a recessed portion adjacent the circular passage through the valve so that there is a space for particulate material which may jam in the valve body to be moved out of the way by the valve gate.